This offer is available for bookings made by December 31, 2017.
There is a $32 mandatory resort fee, so the total rate after tax and fee is $80.50 per night on the $39 room rate and $125.85 per night on the $79 weekend rate.
Full payment is charged at time of booking, but this is a flexible rate with no cancellation penalty up to 3 days before arrival.
There appears to be lots of availability for 2018 dates.
SLS Las Vegas 4 night stay Mon Feb 4 – Thu Feb 7
$321.99 total after tax and resort fees.
I reviewed my stay at this hotel in February 2016.
Loyalty Traveler – Hotel Review SLS Las Vegas, Starwood Tribute Portfolio